site/elfutils/libunistring: Drop patching for iconv and set in site file

The standard macros from gettext for iconv include problematic tests which
we've been patching out adhoc. Stop doing this and set results in the site
files instead which is simpler, more maintainable and peforms better too
as an added bonus.

(From OE-Core rev: 5a3bfdc4af18302cf0e3ea5802fdfefaa7235657)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/elfutils/elfutils_0.183.bb

@@ -14,7 +14,6 @@ SRC_URI = "https://sourceware.org/elfutils/ftp/${PV}/${BP}.tar.bz2 \
            file://0001-dso-link-change.patch \
            file://0002-Fix-elf_cvt_gunhash-if-dest-and-src-are-same.patch \
            file://0003-fixheadercheck.patch \
-           file://0004-Disable-the-test-to-convert-euc-jp.patch \
            file://0006-Fix-build-on-aarch64-musl.patch \
            file://0001-libasm-may-link-with-libbz2-if-found.patch \
            file://0001-libelf-elf_end.c-check-data_list.data.d.d_buf-before.patch \

meta/recipes-devtools/elfutils/files/0004-Disable-the-test-to-convert-euc-jp.patch

@@ -1,42 +0,0 @@
-From cd36f34c722dd0babd7beb13c968aa0780c9f726 Mon Sep 17 00:00:00 2001
-From: Hongxu Jia <hongxu.jia@windriver.com>
-Date: Tue, 15 Aug 2017 17:24:06 +0800
-Subject: [PATCH] Disable the test to convert euc-jp
-
-Remove the test "Test against HP-UX 11.11 bug:
-No converter from EUC-JP to UTF-8 is provided"
-since we don't support HP-UX and if the euc-jp is not
-installed on the host, the dependence will be built without
-iconv support and will cause guild-native building fail.
-
-Upstream-Status: Inappropriate [OE specific]
-
-Signed-off-by: Roy Li <rongqing.li@windriver.com>
-
-Rebase to 0.170
-Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
-
----
- m4/iconv.m4 | 2 ++
- 1 file changed, 2 insertions(+)
-
-diff --git a/m4/iconv.m4 b/m4/iconv.m4
-index aa159c5..d16312b 100644
---- a/m4/iconv.m4
-+++ b/m4/iconv.m4
-@@ -165,6 +165,7 @@ AC_DEFUN([AM_ICONV_LINK],
-       }
-   }
- #endif
-+#if 0
-   /* Test against HP-UX 11.11 bug: No converter from EUC-JP to UTF-8 is
-      provided.  */
-   if (/* Try standardized names.  */
-@@ -176,6 +177,7 @@ AC_DEFUN([AM_ICONV_LINK],
-       /* Try HP-UX names.  */
-       && iconv_open ("utf8", "eucJP") == (iconv_t)(-1))
-     result |= 16;
-+#endif
-   return result;
- ]])],
-           [am_cv_func_iconv_works=yes], ,